Installed Mojave successfully on my laptop. But there are two problems.

I have Lenovo Y50 laptop and successfully installed Yosemite, El Capitan and finally Mojave on it. Mojave guide. But having 2 problems rn:

1- Laptop doesn't sleep in low charge automatically. It just keeps draining the battery till 0% and hence, all work get lost.

2- Usually when I boot macOS, the brightness is set at maximum and speakers, microphone get disabled, only solved by booting again. This happens randomly and frequently.